What is the least common multiple of 9 and 15? Another way to say this is: $\lcm(9, 15) = {?}$
The least common multiple is the smallest number that is a multiple of 9 and 15. We know that 9 x 15 (or 135) is a common multiple, but is it the least common multiple? Write out the multiples of 15 until we find a number divisible by 9. 15, 30, 45, So, 45 is the least common multiple of 9 and 15.